In an electric compressor having a build-in electric motor for driving the compressor, especially in an electric compressor used in a refrigeration system for vehicles, etc., because usually a high-voltage motor is used, from the viewpoint of safety and the like, a structure is required for insulating between the portions of a motor terminal part and the connection section thereof and the portions of a motor housing part and a compressor housing part (that is, a body portion), thereby removing a fear of leak. In such an electric compressor, usually, a connection section between an external terminal for power supply to the built-in electric motor and the end of a wire from a stator of the electric motor is provided, and a structure is frequently employed wherein the connection section is stored in the compressor housing, in particular, in a projected hollow portion extending outward.
Further, even in an electric compressor having a high-voltage motor used in a refrigeration system for vehicles and the like, the above-described connection section is frequently designed similarly in a compressor for general household electric equipment, and in the structure, a terminal connection section is held only by the force of a spring provided to a terminal, and therefore, generally no particular measures for vibration resistance are taken. For example, a terminal and a coupler for a compressor for general household electric equipment are used and the terminal connection section is merely pressed by a spring force, and in most cases, the terminal connection section is not fixed by fixing means like bolts. Therefore, if a great load beyond the spring force is applied, there is a possibility that breakage of the terminal connection section or momentary electrical interruption (a phenomenon that by momentary separation, an electrical connection is interrupted momentarily) may occur. Particularly, in an electric compressor mounted on a vehicle to which an external force due to vibration tends to be applied, such a problem liable to occur. However, since such a structure is simple, it is good in productivity and cost.
On the other hand, as a structure for improving vibration resistance of a motor terminal connection section, for example, as shown in FIG. 4, a structure is also known wherein a resin 103 such as epoxy is injected around a connection section between terminals of an external terminal for power supply 101 and a terminal provided on a terminal end 102 from a stator, and whereby the connection section is formed by molding. A compressor housing 104 is insulated from the terminals by this resin 103. In this structure, because the portion around the terminals is molded by the resin, although the possibility of breakage due to vibration becomes less, since coefficient of linear expansion differs between terminal (made of metal) and resin, the connection section may be deformed in a direction in which the terminals are broken, depending upon the temperature therearound. Further, although the cost for forming the connection section is low because of its simple structure, since it needs time for curing the resin in the line for production, the productivity is low.
Such problems with respect to the connection section exist not only in a simple electric compressor built in with an electric motor for driving its compression mechanism, but also in a hybrid compressor having a built-in electric motor and another external drive source different therefrom (for example, an engine for running a vehicle) as drive sources for compression mechanisms similarly.
For example, as a hybrid compressor used in a refrigeration system for vehicles and the like, a hybrid compressor is proposed wherein a first scroll-type compression mechanism driven only by a prime mover for a vehicle and a second scroll-type compression mechanism driven only by a built-in electric motor are integrally incorporated at a condition of the fixed scrolls of both compression mechanisms back to back (Patent document 1). In such a hybrid compressor, it becomes possible to operate each compression mechanism solely or both compression mechanisms simultaneously, and it becomes possible to obtain an optimum discharge performance depending on current requirements. Even in such a hybrid compressor, there exist the above-described problems on the terminal connection section for the built-in electric motor.
Patent document 1: JP-A-2003-161257
Where, in order to solve the above-described problems, although it has not been disclosed yet, an electric compressor is also proposed by the applicant of the present application wherein the vibration resistance of the terminal connection section for a motor is improved by providing a vibration resistant means, thereby preventing breakage and momentary electrical interruption at the terminal connection section and ensuring good productivity (Patent document 2).
Patent document 2: JP-A-2004-373156